Well, there's one guy who isn't, and he leads the Doctor to...
...the Macra! Let's look at them again.
The Macra are giant crabs. They are ridiculous and I love them. I'm so bummed that this is one of the stories that is missing all four of its episodes. The Macra are quintessential early Doctor Who silly villains. Oh, and the colonists are being mind-controlled while they sleep to forget that the Macra exist and to love working in the gas mines. This works on dumb Ben, but Jamie and Polly don't fall for it. Let's look at the Macra again.
So the Doctor figures out that they breathe the gas from the mines, gets the colonists to rebel, and sneaks out of there before they can put him in charge.
The Second Doctor's personality is really starting to come through. He's growing into the role and turning into the character who is tied for my favorite Doctor.
Companions: Jamie, Polly, Ben
Episode: #34, "The Macra Terror," four parts
Adversary: the Macra
Classic Lines: Jamie: "You don't send a lassie and an old man down to dig." the Doctor: "Old? What do you mean, old? I'm not old, Jamie!"
Tuck This Away to Impress Your Friends: The Macra show up again in the new series episode Gridlock, in which they've devolved as a species into mindless predators.
Next Up: "The Faceless Ones"